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Summary of Contents for 144

Page 1: ...PRIETARY TO WAVETEK THE INFORMATION IN THIS DOCUMENT ISNOT TO BE USEDOR DUPLICATED IN ANY MANNER WITHOUT THE PRIOR APPROVAL IN WRITING OF WAVETEK VS VVETEK SAN DIEGO 9045 Balboa Ave San Diego Calif 92...

Page 2: ...ion 2 1 Electrical Installation 2 1 Operating Controls 2 2 Installation Checks 2 3 Operating Procedure 2 4 Section Three CIRCUIT DESCRIPTION Simplified Block Diagram Analysis Functional Block Diagram...

Page 3: ...nce and repair of this instrument Wavetek s product improvement program ensures that the latest electronic developments are incorporated in all Wavetek instruments by the addition of circuit and compo...

Page 4: ...to drive X Y recorders or the vertical and horizontal deflection circuits of oscilloscopes video monitors etc Varying the triangle symmetry produces a sawtooth or ramp signal with a rise or fall time...

Page 5: ...TRIG IN connector Continuous Sweep Main generator is swept by internal sweep generator so that frequency of 5012 OUTput Is swept from a low frequency established by front panel frequency controls to...

Page 6: ...line method SQUARE WAVE RISE AND FALL TIME terminated in 5012 load Less than 20 nanoseconds limited to 500 V microsecond TOTAL ABERRATIONS Less than 5 1 X7 Environmental TEMPERATURE All specification...

Page 7: ...ac line cord to the mating connector at the rear of the unit NOTICE Unless otherwise specified at the time of pur chase all Wavetek instruments are shipped from the factory with the power transformer...

Page 8: ...l 12 this output provides a fixed 0 to i 5 V sawtooth out put The frequency of this output is controlled by the sweep rate controls 11 When the generator is in continuous Swp Trig Swp or Swp Hold mode...

Page 9: ...wilt decrease the frequency Input impedance is 5 kO 16 Symmetry Control This controls the time sym metry between the positive and negative portions of the output waveform In the full counter clockwis...

Page 10: ...E control 13 Using a shielded cable equipped with BNC connectors connect the SWP GCV OUT connector to the TRIG IN connector and connect the scope to the 50fl OUT connector Set MODE switch to TRIG and...

Page 11: ...mV 15 mV 50 dB 50 mV 5 mV 60 dB 15 mV 1 5 mV 7 With DC OFFSET set to 0 detent position and SYM METRY control set to NORM the output waveform should be a symmetrical waveform oscillating around a zero...

Page 12: ...rator If a positive voltage is applied to the VCG input terminal the frequency will increase from the dial setting A negative voltage will cause the frequency to decrease from the dial setting The VCG...

Page 13: ...dth using the range switch and the main frequency dial 4 Apply a signal to the Trig In BNC Note The SWP GCV ouqiut may be used as a trigger source In this case the sweep time control determines the re...

Page 14: ...generator to cont with sweep mode The frequency will now sweep between the START frequency selected by the main dial and the stop frequency as adjusted by the sweep width If more detailed calibration...

Page 15: ...ading this description Paragraph 3 2 and its sub paragraphs pro vide further descriptions of the functions of the basic circuits in this instrument This paragraph describes briefly the major circuit e...

Page 16: ...are wave and a triangle wave at the same frequency The output frequency is determined by the magnitude of the capacitor selected by the FREQ HZ selector and the magnitude of the positive and negative...

Page 17: ...epetition rate is controlled by the sweep time VARIABLE control R33 and the SWEEP TIME range selector switch The Current Source Switch provides a shunt path to signal ground for the timing capacitor w...

Page 18: ...of a selected wave form is accomplished When in the GATED mode the output of the Trigger Level Comparator Squaring circuit is coupled directly to the Trigger Gate Control The sequence of operation is...

Page 19: ...runs continuously at the minimum frequency set by the FREQ DIAL VERNIER and FREQ HZ selector The Sweep Generator is initially in a standby condition When an input trigger signal is applied at the TRIG...

Page 20: ...agram and if necessary the appropriate portions of the schematic diagrams at the rear of this As shown in Figure 3 6 IC2 is connected as a Summing manual Amplifier to sum the VCG input current through...

Page 21: ...se the current from the current sources will go as low as 50 nA and the source current of ICS and IC6 can not be neglected Therefore a high impedance buffer ampli fier Q26 and Q27 is inserted between...

Page 22: ...positive current will be diverted to the Hysteresis Switch through CR10 and the negative current source will draw current from the timing capacitor through CR8 This action causes a iinear discharge o...

Page 23: ...the voltage at point B and the output voltage will start to go negative Finally when the output has moved far enough negative to pull point A back to zero the collector currents of Q52 and Q53 will a...

Page 24: ...d CRB are switched off and the triangle generator begins to oscillate normally TRIGGER LEVEL COMPARATOR SQUARING CIRCUIT Refer to Figure 3 4 3 10 and the Sweep Board schematic 144 212 at the rear of t...

Page 25: ...becomes negative the 21 current out of the baseline correction circuit stops flowing through CR5 and CR6 removing the effective shunt path of the inte grator in die Main Generator The integrator outpu...

Page 26: ...r Since the collector of Q7A is held at a constant voltage by the reference diode Q8 the collector of Q7B is a current source for the passive integrator Since the collector of Q7A is held at a constan...

Page 27: ...ndary to the bridge rectifiers CR1 through CR8 Filtering is pro vided by Cl C2 CIO and C12 Q9 is connected and operated as a zener reference for the 15 V supply IC1 is a comparator differential amplif...

Page 28: ...sink of the power supply board connected to the rear plate of the unit as the rear plate is also used as a portion of the heat sink for the power transistors NOTICE 4 1 3 Removing the Sweep Board 1 R...

Page 29: ...t Packard 8552A RF Section HewIett Packard 8553L Differential Microvolt dc Voltmeter measurement Counter To 10 MHz 0 1 of reading accuracy NOTE The entire calibration procedure must be read first to d...

Page 30: ...FREQ HZ to X 100 VERNIER to CAL WAVE FORM SELECTOR to SINE FREQ DIAL to 10 and OUTPUT ATTEN to 0 dB 20 Set 30 V P P MAX control to 3 4ths of full CW and connect oscilloscope probe to position of the...

Page 31: ...ected to the oscilloscope set FREQ HZ to X 100K FREQ DIAL to full clock wise extreme and WAVEFORM SELECTOR to SQUARE WAVE 40 Adjust the scope controls for a display speed of 1 ms cm and adjust VERNIER...

Page 32: ...low the trouble shooting procedure outlined below Localize the fault to a specific stage by following the outline in Table 4 2 Then check the dc operating voltages at the pins of the solid state devic...

Page 33: ...dule is malfunctioning and should be replaced First Check Q34 or Q35 for possible trouble The Triangle Generator is not functioning properly Check Triangle Amplifier Hysteresis Switch Diode Gate and V...

Page 34: ...and 2 5 volts If switch does not oscillate proceed as follows e If voltage at gate of Q2 is greater than 1 25 V the voltage at the emitter of Q16 should be 2 5 V and the emitter of Q1 1 should be 2 5...

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